Chest
Volume 113, Issue 3, March 1998, Pages 759-767
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Clinical Investigations in Critical Care
A Randomized Clinical Trial Comparing an Extended-Use Hygroscopic Condenser Humidifier With Heated-Water Humidification in Mechanically Ventilated Patients

https://doi.org/10.1378/chest.113.3.759Get rights and content

Study objective

To determine the safety and cost-effectiveness of mechanical ventilation with an extended-use hygroscopic condenser humidifier (Duration; Nellcor Puritan-Bennett; Eden Prairie, Minn) compared with mechanical ventilation with heated-water humidification.

Design

Prospective randomized clinical trial.

Setting

Medical and surgical ICUs of Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital.

Patients

Three hundred ten consecutive qualified patients undergoing mechanical ventilation.

Interventions

Patients requiring mechanical ventilation were randomly assigned to receive humidification with either an extended-use hygroscopic condenser humidifier (for up to the first 7 days of mechanical ventilation) or heated-water humidification.

Measurements

Occurrence of ventilator-associated pneumonia, endotracheal tube occlusion, duration of mechanical ventilation, lengths of intensive care and hospitalization, acquired multiorgan dysfunction, and hospital mortality.

Results

One hundred sixty-three patients were randomly assigned to receive humidification with an extended-use hygroscopic condenser humidifier, and 147 patients were randomly assigned to receive heated-water humidification. The two groups were similar at the time of randomization with regard to demographic characteristics, ICU admission diagnoses, and severity of illness. Risk factors for the development of ventilator-associated pneumonia were also similar during the study period for both treatment groups. Ventilator-associated pneumonia was seen in 15 (9.2%) patients receiving humidification with an extended-use hygroscopic condenser humidifier and in 15 (10.2%) patients receiving heated-water humidification (relative risk, 0.90; 9 5% confidence interval=0.46 to 1.78; p=0.766). No statistically significant differences for hospital mortality, duration of mechanical ventilation, lengths of stay in the hospital or ICU, or acquired organ system derangements were found between the two treatment groups. No episode of endotracheal tube occlusion occurred during the study period in either treatment group. The total cost of providing humidification was $2, 605 for patients receiving a hygroscopic condenser humidifier compared with $5, 625 for patients receiving heated-water humidification.

Conclusion

Our findings suggest that the initial application of an extended-use hygroscopic condenser humidifier is a safe and more cost-effective method of providing humidification to patients requiring mechanical ventilation compared with heated-water humidification.

Section snippets

Study Location and Patients

The study was conducted at a university-affiliated teaching hospital: Barnes-Jewish Hospital (900 beds). During a 4-month period (October 1996 to January 1997), all patients receiving mechanical ventilation in the medical and surgical ICUs of this hospital were potentially eligible for this investigation. Patients were entered into the investigation if they were older than 17 years and required mechanical ventilation while in the ICU setting. Patients were excluded if they had transferred from

Patients

Three hundred twenty-two consecutive patients requiring mechanical ventilation in the medical and surgical ICUs were enrolled into the study. Nine patients were randomized on two different occasions (their second study admissions were excluded) and three patients were transferred from outside hospitals while receiving mechanical ventilation. Therefore, 310 patients were analyzed, of whom 163 (52.6%) received humidification with an extended-use HCH and 147 (47.4%) received heated-water

Discussion

We found that providing initial humidification to mechanically ventilated patients with an extended-use HCH was safe and more cost-effective compared with providing initial humidification with a heated-water system. The overall rates of ventilator-associated pneumonia and the episodes of ventilator-associated pneumonia per 1,000 ventilator-days were similar between our two study groups (Table 5). Additionally, hospital mortality, deaths directly attributed to ventilator-associated pneumonia,

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    This research was supported in part by an educational grant from Nellcor Puritan-Bennett.

    revision accepted August 25.

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